Comparative numerical investigation of different PVT collector configurations: Energy and exergy analysis

Electrical efficiency of photovoltaic (PV) cells diminishes as cell temperature increases, making photovoltaic thermal (PVT) collectors a viable solution to mitigate this issue while simultaneously providing thermal energy. In this study, a comprehensive numerical analysis of ten configurations of single-inlet, two-inlet, and multi-inlet water-based PVT collectors with vertically or horizontally arranged tubes was conducted using Finite Element Method with COMSOL Multiphysics software. A conventional PV panel was also included in the analysis. To ensure a fair comparison, the tube lengths were kept equal across all configurations. Various energetic and exergetic performance parameters were assessed by varying the flow rate (5–50 l/h), solar radiation (200–1200 W/m2), water inlet temperature (10–40 °C), ambient temperature (15–40 °C), and wind velocity (1–5 m/s). Moreover, the study analyzed the effect of these variables on the pressure drop in the PVT collectors. The analysis revealed that the multi-inlet configurations with both vertically and horizontally arranged tube arrangements, along with the vertically arranged single-inlet configuration, exhibited the best performance in terms of the evaluated parameters. The optimal configuration was the multi-inlet horizontal arrangement for pressure drop perspective. The highest recorded thermal efficiency was 0.61, the maximum overall efficiency reached 0.76, and the peak exergy efficiency was 0.15.